Remote Viewer fails to connect on multiple devices: verify firewall whitelist before escalating

Android

When Remote Viewer fails to connect on multiple devices simultaneously, the session never starts and the permission prompt does not appear on the device screen.

Why this happens

Remote Viewer relies on specific network endpoints for both the screen-sharing session and the push notification that delivers the permission prompt to the device. If your firewall blocks any of these endpoints, the device never receives the prompt and the connection cannot be established. Because the same firewall rules apply to all devices on the same network, a misconfiguration typically affects multiple devices at once.

Steps

1. Confirm the required endpoints with your network team. Open the Esper Firewall Requirements page and locate the Remote Viewer section. Share every listed endpoint and port with your network or firewall administrator and confirm that all of them are allowed for outbound traffic from your managed device network. Pay particular attention to the push notification endpoints — if those are blocked, the permission prompt will never appear on the device even if the session endpoint itself is open.
2. Apply the firewall changes and wait for them to propagate. Ask your administrator to confirm when the rule changes are active. Firewall policy propagation time varies by environment; confirm with your administrator before proceeding.
3. Restart the Esper Agent on the affected devices so it re-establishes its connections under the updated firewall rules. Use one of the following methods:
   • From the Esper Console: Go to Devices & Groups → [Device Name] → Actions and select Restart Agent.
   • On the device directly: Go to Settings → Apps → Esper Agent → Force Stop, then reopen the Esper Agent.
4. Check the installed Esper Agent version. Go to Devices & Groups → [Device Name] → Device Info and note the Esper Agent version. An outdated agent can cause Remote Viewer connectivity issues independent of firewall configuration. If an update is available, apply it via a Blueprint update or through Esper Software Updates before retesting.
5. Test the Remote Viewer connection. In the Esper Console, go to Devices & Groups → [Device Name] → Remote Viewer and select Start Session. Watch the device screen for the permission prompt. Select Allow when it appears. The live screen feed should load in the Esper Console within a few seconds of granting permission.

Verify: The Remote Viewer session should display a live screen feed in the Esper Console within a few seconds of selecting Allow on the device. If the permission prompt appears but the feed does not load, or if the prompt appears on some devices but not others, note which devices are affected and proceed to the next section.

If this doesn't resolve it

If Remote Viewer still fails to connect after all firewall endpoints are confirmed open and the Esper Agent is up to date, collect the following information before contacting support:

• Serial numbers of all affected devices (available under Devices & Groups → [Device Name] → Device Info)
• Esper Agent version installed on the affected devices
• Confirmation from your network administrator that all endpoints in the Firewall Requirements page are whitelisted
• Connection logs captured via ADB, if available:

  adb shell logcat -d | grep -i "remote\|viewer\|esper"

• Whether the issue affects all devices on the network or only a subset, and whether affected devices share a specific network segment or VLAN

Submit this information to Esper Support so the issue can be investigated with full context.

--- Improved title: Remote Viewer won't connect on multiple devices — unblock firewall endpoints

Still need help?

If Remote Viewer still won't connect after verifying your firewall whitelist, please submit a support ticket and include your firewall rules, the affected device serial numbers, and any error messages from the Remote Viewer logs.